Roman blind without any pull rope

ABSTRACT

A Roman blind without any pull rope includes an upper case, a blind cloth, and at least an elastic device. The upper case has a winding shaft in its interior for winding plural ropes attached on an inner surface of the blind cloth for pushing up and down for expanding or shrinking. The elastic device is deposited in the upper case, consisting of a housing and a spring fixed in the housing, a first bevel gear with a shaft and a second bevel gear with a shaft. The first and the second bevel gear engage with each other, and the elasticity of the spring is transmitted orderly to the second bevel gear, the first bevel gear, and to the winding shaft so as to pull up or lower down the blind cloth without necessity of pull ropes. The elasticity of the spring can balance the weight of the blind cloth for keeping the blind cloth stopped at one of many vertical locations.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a Roman blind, particularly to one providedwith an elastic device fixed in an upper case to always supply a Romanblind with rising up strength so as to enable the Roman blind manuallypushed up and down without need of pull ropes.

2. Description of the Prior Art

Conventional Roman blinds generally have an upper case, a blind clothhaving its upper end fixed with the lower side of the upper case, alower rod of the blind cloth having plural pull ropes attachedvertically on the inner surface and their ends fixed in the upper case.The Roman bind cloth can be lowered down or pulled up by handling thepulling ropes.

However, the pulling ropes have a potential danger to hook upaccidentally the neck of a playful child tampering with the pullingropes. So this drawback has to be improved.

SUMMARY OF THE INVENTION

This invention has been devised to offer a Roman blind without any pullrope, which includes an elastic device instead of the pull ropes in theconventional ones for maintaining a blind cloth at any location in thevertical direction in case of pulling down and up manually by itselasticity functioning as a raising force for the blind cloth and thenreleasing the hand off the blind. The elastic device consists of ahousing, a spring fixed in an upper case, a first bevel gear with ashaft, and a second bevel gear with a shaft engaging with the firstbevel gear for transmitting elasticity to a winding shaft combined withthe shaft of the first bevel gear. Then the blind cloth does not needpull ropes, possible to be manually pushed up and down to any locationvertically and released manually to stop at that location because of thebalanced condition caused by the elasticity of the elastic device andthe weight of the blind cloth.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be better understood by referring to theaccompanying drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of a Roman blindwithout any pull rope in the present invention;

FIG. 2 is a perspective view of an elastic device in the presentinvention;

FIG. 3 is an exploded perspective view of the elastic device in thepresent invention;

FIG. 4 is a side cross-sectional view of the elastic device in thepresent invention;

FIG. 5 is a perspective view of the blind cloth being pushed up toshrink in the present invention; and,

FIG. 6 is a perspective view of a second embodiment of a Roman blindwithout any pull rope in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first preferred embodiment of a Roman blind without any pull rope inthe present invention, as shown in FIGS. 1 and 2, includes an elongateupper case 10, a blind cloth 20 and an elastic device 30 as maincomponents combined together.

The elongate upper case 10 consists of an elongate U-shaped frame 11, ashaft base 12 respectively fixed at two side ends of the frame 121, ahexagonal winding shaft 13 combined between the two shaft base 12, and arope winding roller 14 respectively fixed beside each shaft base 12 andcombined and rotating with the winding shaft 13.

The blind cloth 20 has its upper end fixed firmly with the bottom of theframe 11 of the upper case 10, a plurality of horizontal rods 21attached equidistantly spaced apart on an inner surface, two rope ears22 respectively bound on two side portion of each rod 21, two ropes 23respectively fitting through the rope ears 22 of all the rods 21 in thevertical direction and having its lower end connected stably with thelower end of the blind cloth 20 and its upper end connected with twowinding rollers 14 in the upper case 10 so the ropes 13 may be wound onthe winding rollers 14 to force the blind cloth 20 expand down or shrinkup.

The elastic device 30 is fixed properly in the frame 11 of the uppercase 10, consisting of a housing 31, a coiled plate spring 32, a firstbevel gear 33 and a second bevel gear 34. The housing 31 is composed ofan upper plate 31 a and a lower case 31 b, and the upper plate 31 a hasa base 312 fixed on its upper surface, and the base 312 has a firstshaft hole 313. The upper plate 31 a further has a second shaft hole 314perpendicular to the first shaft hole 313 and the lower case 31 b has ahollow inner space 315 with an upper opening to be closed by the upperplate 31 a. The bottom wall of the hollow inner space 315 has a thirdshaft hole 316 aligned to the second shaft hole 314.

The coiled plate spring 32 may be a whirlwind spring or a torsionspring, positioned in the hollow inner space 315 of the housing 31,having certain elasticity.

The first bevel gear 33 has a shaft 331 to fit in the shaft hole 313 ofthe housing 31 and having an outer end fixed with a bevel gear body 332,and the shaft 331 has its center provided with a hexagonal hole 333 tofit with so the shaft 331 may rotate the hexagonal winding shaft 13.

The second bevel gear 34 has a shaft 341 extending in the second shafthole 314 of the housing 31 and then fixed firmly with the coiled platespring 32 so that the elasticity of the spring 32 may rotate the secondbevel gear shaft 341, which has its outer end fixed with the bevel gearbody 342 to engage the first bevel gear body 332.

In using the Roman blind, referring to FIGS. 4 and 5, a user pushes upmanually the bottom of the blind cloth 20 with some force, and then theblind cloth 20 may gradually move up from the bottom, forcing thehorizontal rods 21 orderly folded up. At the same time, the spring 32 ofthe resiliency device 30 has some elasticity to be transmitted to thesecond bevel gear 34, which then rotates the first bevel gear 33 thenthe winding shaft 13, and the winding rollers 14, which then wind up theropes 23 owing to the rope's ends connected with the lower end of theblind cloth 20. As the elasticity of the spring 32 is made to balancewith the weight of the blind cloth 20, the blind cloth 20 may stop atany location if the hand of the user releases the blind cloth 20. In thesame reason, the blind cloth 20 can be lowered manually down to stop atany location in case of releasing the hand.

Further, FIG. 6 shows a second embodiment of a Roman blind without apull rope in the invention, which has almost the same structure, exceptone more elastic device 30 is added to the first one, reinforcing theelasticity for balancing a heavier blind cloth 20. Then a user canselect the first or the second embodiment of a Roman blind without apull rope to suit with a blind cloth of various weights.

The Roman blind according to the invention has the following advantages,as can be understood from the foresaid description.

1. It is not necessary to use a pull rope, possible to avoid potentialdangers the conventional Roman blinds have.

2. The elastic device 30 supplies the blind cloth 20 with moving-upforce, so it is very easy to handle the blind cloth 20 in pushing up orpull down.

3. The raising up force of the elastic device 30 can balance the weightof the blind cloth 20 so the blind cloth 20 can be stopped at anylocation vertically by manual handling of a user, resulting inconvenient effect.

While the preferred embodiments of the invention have been describedabove, it will be recognized and understood that various modificationsmay be made therein and the appended claims are intended to cover allsuch modifications that may fall within the spirit and scope of theinvention.

1. A Roman blind without any pull rope comprising: An upper elongatecase consisting of an elongate U-shaped frame, a winding shaft arrangedin said frame: A blind cloth having an upper end fixed with said uppercase, and plural ropes attached vertically spaced apart on an innersurface, the upper end of said ropes possible to be wound up or down byrotation of said winding shaft so said blind cloth may be expanded downor shrunk up: At least an elastic device fixed in said elongate frame ofsaid upper case, consisting of a housing, a spring member deposited insaid housing, a first bevel gear and a second bevel gear engaging withsaid first bevel gear, said second bevel gear connected with said springmember, said first bevel gear connected with said winding shaft, theelasticity of said spring member transmitted orderly to said first bevelgear, said second bevel gear, said winding shaft, and said ropes to saidblind cloth so the elasticity may balance with the weight of said blindcloth for keeping said blind cloth at the stopped condition at one ofmany locations vertically.
 2. The Roman blind without any pull rope asclaimed in claim 1, wherein said housing is composed of an upper plateand a lower case, said upper plate having a base on its upper surface,said base having a first lengthwise shaft hole for a shaft of said firstbevel gear to extend in, said upper plate having a second shaft holeperpendicular to said first shaft hole for a shaft of said second bevelgear to extend in, said lower case provided with a hollow inner space,said hollow inner space having an upper opening for said upper plate toclose up, said hollow inner space having its bottom wall bored with athird shaft hole aligned to said second shaft hole.
 3. The Roman blindwithout any pull rope as claimed in claim 2, wherein said first bevelgear has the shaft extending in said first shaft hole of said housing,and the outer end of said first bevel gear shaft fixed with a bevel gearbody, said shaft having its lengthwise center portion provided with ahexagonal lengthwise hole as the same shape and size of said windingshaft, said second bevel gear has a shaft extending in said second shafthole of said housing, said second bevel gear shaft having its outer endfixed with a second bevel gear body engaging with said first bevel gearbody.
 4. The Roman blind without any pull rope as claimed in claim 1,wherein said spring member is a whirlwind spring.
 5. The Roman blindwithout any pull rope as claimed in claim 1, wherein said spring memberis a torsion spring.